From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0EB6935CBD2 for ; Tue, 27 Jan 2026 15:48:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769528901; cv=none; b=Xg9HhWhr7qYdR/FoXb5vin2yxr4hhY6nEUrN/iRafJweimTqQZ8kQ8TMVgliJI/R5j0xMw04vGS5sTeXgi+MP9qWN+rXWHuGw/fT2t5w6DIaEdAYnlTR6EmBaMQOI4AR0mPlrKqcbVfMr8XAJptB2kXyb7wn3rJAItTj1lk+330= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769528901; c=relaxed/simple; bh=MyJH6B/DAC2Hks4I0KKh108Lu3whfs1qSGJMxXLIyA0=; h=Mime-Version:Content-Type:Date:Message-Id:From:Subject:Cc:To: References:In-Reply-To; b=K4CuAO6+drhZcOfUyZaDa1xn7jJw1tgz/x2CIYwxFMkRcAjCqiXeFjKVqeUoX7Ld8Bfc7EYCDG9qFVmzsJy1RP+FxU1K14+9G+8ukSsby1bEaNgBVAVKDcfEmTGoB4HAtNb4a2hWv884z+d/JX+gCz2NGN1Mpg4svsbCk37nmhQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=fpV21aWq; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="fpV21aWq" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 772884E422D3; Tue, 27 Jan 2026 15:48:17 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 4ADC8606F5; Tue, 27 Jan 2026 15:48:17 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 8AB21119A8637; Tue, 27 Jan 2026 16:48:12 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1769528896; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=OxkgHIERK1QMMyBS9ryD4i6d6w+RIzeILS9CMd6za+4=; b=fpV21aWqssDyfTLubMz3GX7FBO/K944DIV7FsDzkeJY1zGQoT4g+hFHhUQktqnCgHWT8JK ef2tYOjMpJNp0jZxNhVUKkKiLv2zBKwzsaKt4qNudaYDxRlQzX3IjggSJTybDZ03YBxSrl UgwP8HK5I51PFp2oBmEwUE+KgmX2iWgtEv1dQzHuKfrM/xR+30opbvPBwLVLeSWPIV7YO8 NqYZ1SFnffF1HjucvPOJIaSUJ3BLVKjhfVaBuov/92yB3qjZv8DiWpdBp+rl2nJjnynCxY F/27PHKDrXi9N+9TDFdqkbGejV3JyzYSfOMdMGTUatLdwv8mCpO2bmqZ+5MJHg== Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Tue, 27 Jan 2026 16:48:11 +0100 Message-Id: From: =?utf-8?q?Th=C3=A9o_Lebrun?= Subject: Re: [PATCH net-next 3/8] cadence: macb: Add page pool support handle multi-descriptor frame rx Cc: , "Nicolas Ferre" , "Claudiu Beznea" , "Andrew Lunn" , "David S. Miller" , "Eric Dumazet" , "Jakub Kicinski" , "Paolo Abeni" , "Lorenzo Bianconi" , =?utf-8?q?Gr=C3=A9gory_Clement?= , "Thomas Petazzoni" To: "Paolo Valerio" , =?utf-8?q?Th=C3=A9o_Lebrun?= , "Andrew Lunn" X-Mailer: aerc 0.21.0-0-g5549850facc2 References: <20260115222531.313002-1-pvalerio@redhat.com> <20260115222531.313002-4-pvalerio@redhat.com> <4c74c2c4-7a47-45ff-be17-485e0702cc37@lunn.ch> <87cy315lru.fsf@redhat.com> <840fd286-779e-4130-b544-913116c97a29@lunn.ch> <87qzrdecs1.fsf@redhat.com> <87ldhkexvq.fsf@redhat.com> In-Reply-To: <87ldhkexvq.fsf@redhat.com> X-Last-TLS-Session-Version: TLSv1.3 On Tue Jan 27, 2026 at 12:51 AM CET, Paolo Valerio wrote: > On 26 Jan 2026 at 07:45:29 PM, Th=C3=A9o Lebrun = wrote: >> On Mon Jan 26, 2026 at 3:29 PM CET, Andrew Lunn wrote: >>>> > I was more interested in plain networking, not XDP. Does it perform >>>> > better with page pool? You at least need to show it is not worse, yo= u >>>> > need to avoid performance regressions. >>>>=20 >>>> I retested with iperf3. The target has a single rx queue with iperf3 >>>> running with no cpu affinity set. >>>>=20 >>>> | | 64 | 128 | >>>> | baseline | 273 | 545 | >>>> | pp (page) | 273 | 544 | >>>> | pp (2 frags) | 272 | 544 | >>> >>> So no real difference. That is unusual, it is typically faster, or if >>> it is always doing line rate, it uses less CPU time. That might >>> suggest the page pool integration is not optimal? >> >> One more data point. I get line rate with & without page_pool so below >> are CPU times from /proc/stat: >> >> upstream pp >> user 1 1 >> system 179 91 (!!!) >> idle 7874 7303 >> softirq 35 37 >> >> 16K pages on Mobileye EyeQ5 (MIPS), 7 fragments per page. >> >> Paolo shared 64 versus 128 measurements but I am unsure what those stand >> for; I doubt it can be packet size as xdp-bench does not have it as a >> parameter. https://man.archlinux.org/man/extra/xdp-tools/xdp-bench.8.en > > 64 and 128 are packet size in bytes. > For the first test I used xdp-trafficgen on the sender side and > xdp-bench (skb-mode) to count the drops in pps on my board. > > For the stack test I used iperf3 (UDP) similarly with 64 and 128 for the > length option. | | 64 | 128 | | baseline | 75.3 | 145 | | page_pool | 79.3 | 154 | Call is: iperf3 -c $IP -u -A2 -b1G -l64 # or -l128 CPU affinity is important. I get approx -30% on CPU0 (where IRQs land) and -12% on CPU1 (2nd thread of CPU0). I looked at ftrace function_graph and it looks sensible. Baseline spends 16% of macb_rx_poll() in gem_rx_refill(). This goes down to 10% with page_pool. Thanks, -- Th=C3=A9o Lebrun, Bootlin Embedded Linux and Kernel engineering https://bootlin.com